what is the function of a turing machine

The main question asked me to build a certain turing machine such that given a word w over {0,1}* the turing machine accepts all such words and ends in accept state with the tape string = the word apended with the number of zeros in it. I built the state diagram of this turing machine..

But now there is a question next to it which say something like –

  1. What is the function the machine you build computes ??

I dont understand what this means ?? What i can think of is that the function the question talks about is the transition function… and that just copies 0’s from w to the end of it… it doesnt computes as such anything..

Any lights on the above ??